: an abnormal condition of reduced pigmentation affecting various animals (such as birds, mammals, and reptiles) that is marked by overall pale color or patches of reduced coloring and is caused by a genetic mutation which inhibits melanin and other pigments from being deposited in feathers, hair, or skin

Examples of leucism in a Sentence

Recent Examples on the Web
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According to the San Diego Zoo Wildlife Alliance, their snowy feathers are the result of a rare genetic condition called leucism, which reduces pigmentation in the plumage while leaving the birds with their normal eye color. — Moná Thomas, PEOPLE, 26 June 2026 Some studies suggested potential ecological costs, but others, including our own work on deep-sea species such as the angular rough shark, showed that conditions like albinism or leucism do not necessarily compromise overall health. — Melissa Cristina Márquez, Forbes.com, 29 May 2026 Piebald is the common name for the genetic mutation known at leucism, said Brad Westrich, mammologist with the Indiana Department of Natural Resources. — Karl Schneider, IndyStar, 15 May 2026 White bison can occur through several rare genetic conditions, including leucism, which reduces pigmentation but does not necessarily produce a true albino animal. — Nick El Hajj, Des Moines Register, 8 May 2026 See All Example Sentences for leucism

Word History

Etymology

borrowed from German Leucismus, from Greek leukós "clear, white" + German -ismus -ism — more at light entry 1

First Known Use

1878, in the meaning defined above

Time Traveler
The first known use of leucism was in 1878

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Cite this Entry

“Leucism.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/leucism. Accessed 29 Sep. 2026.

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